Added implementation of the node monitoring functions.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3065 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/storage/NodeMonitor.cpp

@@ -0,0 +1,217 @@
+//----------------------------------------------------------------------
+//  This software is part of the OpenBeOS distribution and is covered 
+//  by the OpenBeOS license.
+//---------------------------------------------------------------------
+
+#include <AppMisc.h>
+#include <Looper.h>
+#include <Messenger.h>
+#include <NodeMonitor.h>
+
+// TODO: Tests!
+
+// private libroot.so functions
+
+/*!	\brief Subscribes a target to node and/or mount watching.
+
+	Depending on \a flags, different actions are performed. If flags is \c 0,
+	mount watching is requested. \a device and \a node must be \c -1 in this
+	case. Otherwise node watching is requested. \a device and \a node must
+	refer to a valid node, and \a flags must note contain the flag
+	\c B_WATCH_MOUNT, but at least one of the other valid flags.
+
+	\param device The device the node resides on (node_ref::device). \c -1, if
+		   only mount watching is requested.
+	\param node The node ID of the node (node_ref::device). \c -1, if
+		   only mount watching is requested.
+	\param flags A bit mask composed of the values specified in
+		   <NodeMonitor.h>.
+	\param port The port of the target (a looper port).
+	\param handlerToken The token of the target handler. \c -2, if the
+		   preferred handler of the looper is the target.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+extern "C" status_t _kstart_watching_vnode_(dev_t device, ino_t node,
+											uint32 flags, port_id port,
+											int32 handlerToken);
+
+/*!	\brief Unsubscribes a target from watching a node.
+	\param device The device the node resides on (node_ref::device).
+	\param node The node ID of the node (node_ref::device).
+	\param port The port of the target (a looper port).
+	\param handlerToken The token of the target handler. \c -2, if the
+		   preferred handler of the looper is the target.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+extern "C" status_t _kstop_watching_vnode_(dev_t device, ino_t node,
+										   port_id port, int32 handlerToken);
+
+
+/*!	\brief Unsubscribes a target from node and mount monitoring.
+	\param port The port of the target (a looper port).
+	\param handlerToken The token of the target handler. \c -2, if the
+		   preferred handler of the looper is the target.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+extern "C" status_t _kstop_notifying_(port_id port, int32 handlerToken);
+
+
+// actual implementation
+
+// watch_node
+/*!	\brief Subscribes a target to node and/or mount watching, or unsubscribes
+		   it from node watching.
+
+	Depending of \a flags the action performed by this function varies:
+	- \a flags is \c 0: The target is unsubscribed from watching the node.
+	  \a node must not be \c NULL in this case.
+	- \a flags contains \c B_WATCH_MOUNT: The target is subscribed to mount
+	  watching.
+	- \a flags contains at least one of \c B_WATCH_NAME, \c B_WATCH_STAT,
+	  \c B_WATCH_ATTR, or \c B_WATCH_DIRECTORY: The target is subscribed to
+	  watching the specified aspects of the node. \a node must not be \c NULL
+	  in this case.
+
+	Note, that the latter two cases are not mutual exlusive, i.e. mount and
+	node watching can be requested with a single call.
+
+	\param node node_ref referring to the node to be watched. May be \c NULL,
+		   if only mount watching is requested.
+	\param flags Flags indicating the actions to be performed.
+	\param target Messenger referring to the target. Must be valid.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+status_t
+watch_node(const node_ref *node, uint32 flags, BMessenger target)
+{
+	status_t error = (target.IsValid() ? B_OK : B_BAD_VALUE);
+	if (error == B_OK) {
+		BLooper *looper = NULL;
+		BHandler *handler = target.Target(&looper);
+		error = watch_node(node, flags, handler, looper);
+	}
+	return error;
+}
+
+// watch_node
+/*!	\brief Subscribes a target to node and/or mount watching, or unsubscribes
+		   it from node watching.
+
+	Depending of \a flags the action performed by this function varies:
+	- \a flags is \c 0: The target is unsubscribed from watching the node.
+	  \a node must not be \c NULL in this case.
+	- \a flags contains \c B_WATCH_MOUNT: The target is subscribed to mount
+	  watching.
+	- \a flags contains at least one of \c B_WATCH_NAME, \c B_WATCH_STAT,
+	  \c B_WATCH_ATTR, or \c B_WATCH_DIRECTORY: The target is subscribed to
+	  watching the specified aspects of the node. \a node must not be \c NULL
+	  in this case.
+
+	Note, that the latter two cases are not mutual exlusive, i.e. mount and
+	node watching can be requested with a single call.
+
+	\param node node_ref referring to the node to be watched. May be \c NULL,
+		   if only mount watching is requested.
+	\param flags Flags indicating the actions to be performed.
+	\param handler The target handler. May be \c NULL, if \a looper is not
+		   \c NULL. Then the preferred handler of the looper is targeted.
+	\param looper The target looper. May be \c NULL, if \a handler is not
+		   \c NULL. Then the handler's looper is the target looper.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+status_t
+watch_node(const node_ref *node, uint32 flags, const BHandler *handler,
+		   const BLooper *looper)
+{
+	status_t error = B_OK;
+	// check looper and handler and get the handler token
+	int32 handlerToken = -2;
+	if (handler) {
+		handlerToken = _get_object_token_(handler);
+		if (looper) {
+			if (looper != handler->Looper())
+				error = B_BAD_VALUE;
+		} else {
+			looper = handler->Looper();
+			if (!looper)
+				error = B_BAD_VALUE;
+		}
+	} else if (!looper)
+		error = B_BAD_VALUE;
+	if (error == B_OK) {
+		port_id port = _get_looper_port_(looper);
+		if (flags == B_STOP_WATCHING) {
+			// unsubscribe from node node watching
+			if (node) {
+				error = _kstop_watching_vnode_(node->device, node->node, port,
+											   handlerToken);
+			} else
+				error = B_BAD_VALUE;
+		} else {
+			// subscribe to...
+			// mount watching
+			if (flags & B_WATCH_MOUNT) {
+				error = _kstart_watching_vnode_(-1, -1, 0, port, handlerToken);
+				flags &= ~B_WATCH_MOUNT;
+			}
+			// node watching
+			if (error == B_OK && flags) {
+				error = _kstart_watching_vnode_(node->device, node->node,
+												flags, port, handlerToken);
+			}
+		}
+	}
+	return error;
+}
+
+// stop_watching
+/*!	\brief Unsubscribes a target from node and mount monitoring.
+	\param target Messenger referring to the target. Must be valid.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+status_t
+stop_watching(BMessenger target)
+{
+	status_t error = (target.IsValid() ? B_OK : B_BAD_VALUE);
+	if (error == B_OK) {
+		BLooper *looper = NULL;
+		BHandler *handler = target.Target(&looper);
+		error = stop_watching(handler, looper);
+	}
+	return error;
+}
+
+// stop_watching
+/*!	\brief Unsubscribes a target from node and mount monitoring.
+	\param handler The target handler. May be \c NULL, if \a looper is not
+		   \c NULL. Then the preferred handler of the looper is targeted.
+	\param looper The target looper. May be \c NULL, if \a handler is not
+		   \c NULL. Then the handler's looper is the target looper.
+	\return \c B_OK, if everything went fine, another error code otherwise.
+*/
+status_t
+stop_watching(const BHandler *handler, const BLooper *looper)
+{
+	status_t error = B_OK;
+	// check looper and handler and get the handler token
+	int32 handlerToken = -2;
+	if (handler) {
+		handlerToken = _get_object_token_(handler);
+		if (looper) {
+			if (looper != handler->Looper())
+				error = B_BAD_VALUE;
+		} else {
+			looper = handler->Looper();
+			if (!looper)
+				error = B_BAD_VALUE;
+		}
+	} else if (!looper)
+		error = B_BAD_VALUE;
+	// unsubscribe
+	if (error == B_OK) {
+		port_id port = _get_looper_port_(looper);
+		error = _kstop_notifying_(port, handlerToken);
+	}
+	return error;
+}
+

src/kits/storage/storage.src

@@ -11,6 +11,7 @@ STORAGE_KIT_SOURCE =
 	MimeType.cpp
 	Node.cpp
 	NodeInfo.cpp
+	NodeMonitor.cpp
 	OffsetFile.cpp
 	Path.cpp
 	Query.cpp